Incandescent lamp



' Dec. 3, 1935.

L. G. SOVULEWSKI ET AL 2,022,747

INCANDESCENT LAMP Filed July 6, 1954 INVENTORaS 771 r. [Y A TTORNEYD Patented Dec. 3, 1935 UNITED STATES mcmsscen'r nmur Lawrence Gabriel So'vnlewski, orange, and

George Martin Booth, Plainfield, N. J., assi on to Wallace 86 TicrnanPi-oducts, Inc., Bellevillc, N. J., a corporation of New'Jersey Application July 6, i934, Serial No. 733,968

8 Claims. (Cl. 176-16) This invention relates to incandescent lamps; more specifically to incandescent lamps for use in optical systems, such as, for example, Fresnel lens systems, wherein it is desired that as large a proportion of the total light emitted by the lamp be distributed substantially evenly and horizontally around an axis extending vertically through the base of the lamp.

One of the objects of the invention is to provide a supporting and/or current-conducting means for a filament system of an incandescent lamp which shall permit the desired distribution of light from the filament system. Other objtcts and advantages will appear as the invention is hereinafter disclosed.

Referring to the drawing, which illustrates what we now consider a preferred form of our invention:

Fig. 1 is an elevation, partly in section, of a part of a lamp embodying one form of our invention.

Fig. 2 is a side elevation of a portion of the structure shown in Fig. 1. i

Fig. 3 is a top plan view of a portion of the structure shown in Fig. 1.

The lamp shown in Figs. 1 to 3 comprises a sealed transparent bulb or hollow container III of glass or other suitable material, adapted to be secured at its lower end in or to a base (not shown) and having a re-entrant portion H through which the current-conductors or wires l2 and I3 are led. It will be understood the wires l2 and I3 are suitably sealed in the glass container so as to make it possible for the container to retain the desired degree of vacuum or gas pressure within it. The lamp comprises a filament system, in this case a vertical filament H, which when heated by passage of suitable electric current, becomes incandescent. and emits light. The particular filament shown is a helical wire of suitable material, such as drawn tungsten or other material; the axis of the filament being vertical when the lamp is used in optical systems of the class referred to above. Such a vertical filament will, when incandescent, emit light radially and horizontally from its axis substantially uniformly.

Heretorore the construction of 'the'supporting and/or current-conveying means have been such as to interfere objectionably' with the desired evenness or uniformity of distribution of light emanating from the filament system. This objetion has been overcome by our invention.

In the form of our invention now being described, the wire I3 is extended upwardly and has a helical portion l5 extending from adjacent the lower end of the filament H to the upper end thereof. The supporting element l3l5 has an offset H5 at its upper end to which the upper end 5 of the filament I4 is electrically and mechanically connected. The element- |3l5-l6, in the form of device shown, serves not only as a supporting element for the upper end of the filament but also as a current-conveying conductor. 10

v The lower end of the filament is electrically and mechanically connected to an oifset of the wire I2.

Thus it will be understood that the elements I! and l3-l5|6 not only support the filament l4 16 but serve also to convey electric current to and from the filament. I

The noteworthy feature is that by virtue of the helical configuration of the supporting element at IS, the desired uniform distribution of 20 light emanating from the filament l4 radially and horizontally is not seriously disturbed. The radius of the helix I5 is as large as possible, consistent with practical considerations of manufacture, strength and the desired approach to 25 ideal conditions of light distribution as dictated by the particular service to which the lamp is to be put. The angle 25 (see Fig. 3) subtended by the helical portion [5 may be greater or less than that shown depending upon similar factors. 30

In lamps embodying our invention, the supporting and/ or current-conveying means does not objectionably or materially obstruct the light emitted by the filament in any direction. Thus, when looking horizontally toward the vertical 35 filament from any direction, the filament is not totally obscured since the portion l5 does not screen the filament at more than one point, in the preferred form of the invention. 1

In accordance with the provisions of the patent statutes, we have herein described the principle of operation of ourinvention, together with the apparatus which we now consider to represent the best embodiments thereof, but we desire to have it understood that the apparatus disclosed is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combinations and relations described, some of these may be altered and others omitted and some of the features of each modification may be embodied in the others without interfering with the .more general results outlined, and the invention extends to such use within the-scope of the appended claims.

through which light from the light source may pass in planes perpendicular to said optical axis, the said portion of said rod member being a three-dimensional curve and angularly intersecting all of said last-mentioned planes, to minimize blocking of light emission in said planes.

2. An incandescent lamp comprising in combination, a vertical filament, supporting means connected to said filament at one end thereof, and a current-conducting supporting rod connected to the opposite end of said filament and to said supporting means, the said supporting rod being a three-dimensional curve and being inclined at its intersection with all horizontal planes which lie between the upper and lower ends of the filament.

3. In a Fresnel lens system for emitting light which, in planes at right angles to a straight line constituting the optical axis of the system, is substantially radially uniform; the combination, of an incandescent light source having a support at one end thereof and a supporting member connected to the opposite end of said light source and having a portion extending from one end of said light source to the other end thereof, the said portion of said member being a threedimensional curve and being inclined with respect to all planes which are perpendicular to the said optical axis and which are intersected by the said portion of said member.

4. An incandescent lamp comprising in combination, a vertical filament, a supporting element connected to said filament at one end thereof, and a second supporting element connected to the opposite end of said filament and terminating adjacent the first mentioned supporting element,

the said second supporting element having a portion which is a three-dimensional curve inclined at its intersection with all horizontal planes which lie between the upper and lower ends of the filament. '5

5. An incandescent lamp comprising in combination, a vertical filament, a supporting element connected to said filament at one end thereof, and a second supporting element connected to l the opposite end of said filament and having a 10 helical portion disposed between a pair of horizontal planes respectively perpendicular to the filament at its ends.

6. An incandescent lamp comprising in combination, a vertical filament, a lead-in wire-connected to said filament at one end thereof,and a second lead-in wire connected to the opposite end of said filament, the said second lead-in wire having a helical portion disposed between a pair of horizontal planes respectively perpendicular to the filament at its ends.

7. In a Fresnel lens system for emitting light which, in planes at right angles to a straight line constituting the optical axis of the system, is substantially radially uniform; the combination of an incandescent light source having a support at one end thereof, and a current-conducting member connected to the opposite end of said light source and having a portion extending from one end of said light source to the other end thereof, the said portion of said member being a three-dimensional curve which intersects a plurality of planes in which light is emitted perpendicularly to the said optical axis, and said portion being inclined with respect to all said inter- 5 sected planes.

'8. An incandescent lamp comprising in combination, a vertical filament, a current-conducting supporting element connected to said filament at one end thereof, and a helical current-con- 40 ducting supporting element connected to the opposite end of said filament, and extending helically Within the space between a pair of planes respectively perpendicular to'the filament at its ends.

LAWRENCE GABRIEL SOVULEWSKI. GEORGE MARTIN BOOTH. 

